02 x5 3.0i w/o or removed air suspension, getting Self-Level Inactive

[omgwtf]

Hello to all, thanks in advance for your time.
I recently purchased a 2002 x5 3.0i and I'm bringing it up to par.
The air pump, tanks etc is missing in the spare tire compartment.
I recently pulled all 4 wheels off and did a search to locate the level sensor, but none were found. Not even the wires going to them.
During the search I noticed that all 4 shocks/struts are gas charged.
"Self-Level Inactive" is always on.
How do I reset/remove this error.
Thanks!